Paper pulp extractor



Nov. 27, 1934. .'v. RIV-:ESE 'Er AL f 1,981,924

' PAPER PULP EXTRACTOR Filed June 6, 1951 www Patented Nov. 27, 1934 UNITED STATES 1,981,924. rma .PULP Ex'rmic'ron Lemuel Y. Reese andGeorge W. Johnson, (2in--y cinnati, ,0hio, -assignors to -Laundry Machinery Company.

Ohio, a corporation of Ohio The American Cincinnati,

Application. June 6, '1931, Serial No. 542,374

I 1 Claim. (CL 233-.-19)

Our invention relates to centrifugal extractora, 1 and particularly, to. an apparatus embodying centrifugal action for freeing paper pulp from im purities accordingt'o the specic gravity of the impurities, disposing of a part of the impurities, and delivering the paper pulp in a purified state to the paper making machines.

Centrifugal machinesof this character usually embody Ain addition to a base or curb and a |01 source of supplyv for untreated paper pulp, a ro- .tatable basketl having a solid wall with means provided thereon for retarding the normal tendency of the pulp to flow upwardly in order to subject the pulp to centrifugal action over such l5 period of time that the impurities and pulp will be separated, a means adjacent the outer wall of the basket for trapping the heavier impurities,

and a skimming ring that is employed for skimming off and holding the lighter weight impurities forming the inner stratum of the load within the basket, the purified paper pulp, made up of clean iibers and water only, forming the center stratum and being delivered continuously into a volute as untreated pulp is fed into the basket.

z5 It is well understood that centrifugal action divides the mass up into the heavier stratum including those parts having the greatest specific gravity, an intermediate stratum which is normally the purified paper pulp, and an inner stratum vmade up of impurities of lesser specific gravity. In previous machines, the skimming ring, while functioning to skim oiI the lighter weight impurities, has embodied no means for providing a sumcient storage space or for effecting complete disposal of uthe accumulation o f lightimpurities skimmed from the pulp stream during the normal intervals between cleaning periods. That is, previous designs of skimming rings with their limited capacities have permitted i0 the light weight impurities to escape or overow the skimming ring and ow out of the machine with the otherwise puried paper pulp, causing the quality of the pulp to `be lowered.

It is the object of our invention to provide adi5 justable means for continuously skimming the lighter weight impurities from the inner portion of the rising stratum or column of purified pulp and for disposing of these impurities by centrifugal action which cari-ies them over into a second volute separate and apart from the volute into which the purified paper pulp flows. From this second volute, the lighter weight impurities may be delivered `to any desired point.

Various other objects and advantageous fea.- i, tures of our invention may be seen in the following description and one `embodiment thereof may be seen in the accompanying drawing wherein similar characters of reference designate corresponding parts, and wherein:

Fig.` 1 is a view partly in section 'and partly 60 in elevation, showing an apparatus constructed in accordance with our invention; Fig. 2 is a top plan view of the apparatus shown in Fig. 1 with the power unit and supporting means therefor removed; and Fig. 3 is a sectional view show- 65- ing the course taken by the various strata having different specific gravities during the operation of the apparatus in which the heavier impurities are driveninto a bed of pulp adjacent I the wall of the basket, the puriiied pulp iiows 'I0 into one vol'ute, and the lighter weight impurities are skimmed away from the puried strata and carried away from the machine by means of a second volute.

Referring to the drawing, we have shown a 7l!4 centrifugal extractor consisting of the usual curb 1 supported by suitable base members 2 and adapted to receive a rotatable basket 3 mounted on aspindle 4 that rotates in a bearing 5 carried by the curb 1 and has its opposing end at- 80 tached to a drive shaft 6 that forms a part of a suitable motor or power unit '7. As shown, this motor or power unit is pi'votally mounted in a pivoted gimble ring 8, supported by suitable uprights 9. which permits precession of the spindle 4 during the operation of the apparatus. v

As is customary in such apparatus, suitable circumferential baffle plates or anges 10 are disposed within the basket 3 for the purpose of retarding the upward flow of pulp and also for building up a pulp mat or bed in which the heavier impurities driven from the pulp during the centrifugal operation of the basket will be imbedded and thereby retained in the basket until such time as it may be found convenient to stop the machine and remove the impurity laden pulp mat or bed from the rotatable basket. The top of the basket is provided with an annular ring 11 'having an overhanging portion 12 to retain the pulp mat or heavier impurities and prevent them from owing out of the basket and an overhanging portion 13 which acts as a guide for directing the puriiied paper pulp into a volute 14 and also as a guard means for preventing the pulp from falling downwardly between the curb and basket.

In accordance with our invention, an annular skimmer ring 15 is provided at the top of the rotatable basket 3 and is suspended from the top of the curb 1 as by means of the bolts 15'. As

shown the skimmer ring may be spaced at the will of the operator the varying distances from the innermost edges of the overhanging portion 12 to skim off or separate the lighter impurities from the strata hereinbefore described by the simple expedient of adiusting the screw bolts 15. Such ability to regulate the thickness of the annular orifice thus created between the skimming ring and the overhanging portion 12 through which the purified paper pulp flows., is of the utmost importance in that, when properly adjusted to the rate of how of paper pulp through the machine, the curved `lip of the skimmer ring will properly separate the lighter impurities from the puried pulp stratum whereby such lighter impurities will travel upwardly over the curved surface 16 of the.

skimmer ring and into a second volute 17, this action being brought about by centrifugal action due to rotation of the basket. From the volute 17, the lighter impurities may be conveyed to and discharged at any desired point. The curb l is shown as being provided with a suitable cover 18 although this is not absolutely essential to the satisfactory operation of the machine.

In the operation of the apparatus, paper pulp of any type from the usual beaters is fed into the basket 3 through a pipe 19 which has its outlet opening near the bottom of the basket, the dow of paper pulp being preferably started after the basket is rotating at a speed which will produce Asufficient centrifugal effect to drive the impurities heavier than the weight of the fibers in the paper pulp into a bed or mat of pulp which immediately forms on the inner surface of the basket wall between the circumferential flanges 10 vas shown at 20 in Fig. 3. While this action is taking place, a stratum of puried pulp 21 will form adjacent the mat 22 containing the heavier impurities, and this stratum of purified pulp will move upwardly as more'raw pulp is fed into the bottom of the basket through the pipe 19. At the same time, the lighter weight impurities which are of such low specific gravity that they are affected only slightly by centrifugal force will yield to the action oi' otation and rise along with but on the inner side of the rising stratum'of purified pulp 22 until they encounter the curved lip of the skimming ring 15 whereupon they will be carried by centrifugal action over the .top of the skimming ring 15 into the volute 17. Onv stopping the rotation of thel basket, such basket may be cleaned by electing the sesV ' a means for purifying paper pulp by separately removing both. the heavier and the lighter impurities therefrom by centrifugal action and have provided ameans for eliminating the vpossibility of the lighter impurities again entering the puri'- fied paper pulp by providing a separate discharge into which the lighter impurities are carried. The water content of the lighter impurities is so small that its removal with the lighter impurities can easily be compensated for in the further preparation of the untreated paper pulp or in the maintenance of the proper consistency of the treated paper pulp after such pulp is delivered from the machine.

What we claim is:

Apparatus for purifying paper pulp, comprising a casing, a basket rotatably mounted in said casing, means for rotating said basket, means for delivering pulp to the lower portion thereof for treatment by centrifugal action whereby the pulp and impurities will be separated into vertically moving annular strata according to their various specific gravities, a plurality of vertically spaced imperforate circumferential anges projecting inwardly equal distances from the wall of said basket to create and maintain a mat on the basket wall into which the impurities of greater specific gravity than pure pulp are driven and trapped, the topmost flange extending outwardly from the basket to discharge pure pulp, an annular skimming ring for separating impurities of less specific gravity than the pulp and segregating them therefrom, said skimming ring extending horizontally over the topmost flange and bending at its inner edge toward said flange, means for adjusting said skimming ring relative to the topmost flange whereby to permit the discharge opening for the pure pulp to be regulated in proportion to the rate of rotation of the basket and upward flow of the pulp stream, and the upper surface of said skimming ring serving to deliver the stratum of impurities of less specific gravity than the pulp from the basket.

LEMUEL V. REESE. GEORGE W, JOHNSON. 

